The use of disposable water treatment elements such as filters is well-known. One type of such filter is the form of a solid porous cylinder having a hollow center. When such an element is employed, the water or other liquid to be treated or filtered flows radially through the wall of the cylinder between its exterior and its hollow core. Examples of such an element are the well-known ceramic filter and the extruded solid activated carbon filters made by the method and apparatus disclosed in Koslow U.S. Pat. Nos. 5,189,092; 5,249,948; and 5,331,037. See also the co-pending U.S. patent application Ser. No. 08/607,294 filed Feb. 26, 1996 of Koslow, et al (pending).
It is well-known that the most efficient filtration is achieved with a relatively long but thin-walled filter element. For example, a long and thin cylinder will always display a lower pressure drop that a short and fat cylinder of the same volume of active ingredient, both because the flow area is larger and the thickness of the medium through which the fluid flows is reduced. However, this presents a problem, especially when the element is employed in a domestic water filtration unit such as might be maintained at a kitchen or bathroom sink. In order to achieve the desired flow volume, a long and ungainly filter element would be required. A second problem is that the changing of filter elements in the conventional domestic filter housing is a messy job often requiring tools and proving very difficult to open because of the large diameter pressure vessels with large threads and compression gaskets. Entirely new problems of space and convenience would emerge when using an exceptionally long filter element. Accordingly, it is a primary object of the present invention to provide an improved liquid treating apparatus and, more specifically, a water filtration apparatus which has the desirable characteristics of a thin-walled, hollow, cylindrical filter element but in a compact configuration. Another object is to provide such an apparatus wherein the filter element may be easily replaced and disposed of with a minimum of mess and water spillage. Another object is to provide such an apparatus wherein the filter elements are so arrayed as to present a relatively flat configuration more readily handled and stored than the usual prior art round array. Other objects, features, and advantages will become apparent from the following description and appended claims.